Diaphragm pump



W. C. CARTER DIAPHRAGM PUMP Dec. 25, 1934.

Filed March 30, 1934 m Mm MM. m WW m X w 0 3 l 7 m y E B I //I\\.\ 1 l I I n I m 4/ m Z a I! u u Cami W W run. m i L. 1

ATTORN E Y5 Patented Dec. 25, 1934 UNITED STATES PATENT OFFICE 11 Claims.

This invention relates to diaphragm pumps of the type that are used for supplying liquid fuel to internal combustion engines and other fuel consuming-apparatus, my present application being a continuation in part of my application Serial No. 657,358, filed February 18, 1933, patented May 15, '1934, No. 1,958,509. r The object of my present invention is to provide a diaphragm pump in which the inlet valve of the pump is mounted inor carried by a removable cap or cover for a fuel reservoir or sediment trapping chamber that is arranged between the pumping chamber and, the supply pipe through which fuel is delivered to the pump.

Another object is to provide a diaphragm fuel pump of the kind just described, which is equipped with a screen or straining device for the fuel passing to the pumping chamber, arranged so that said screen is accessible when the valve carrying cap of the fuel reservoir or sediment trapping chamber is removed.

And still another object of my invention is to provide a housing structure for diaphragm pumps that is inexpensive to construct, easy to assemble and disassemble and of such design that the intake valve of the pump is easily accessible for inspection, repair or replacement.

The figure of the drawing is a vertical sectional view of a diaphragm pump embodying my present invention.

In the accompanying drawing, A, B and C designate three members that co-operate with each other to form a housing structure for the various elements of the pump, such as the pump ing chamber 1, the diaphragm 2, the operating mechanism for the diaphragm designated as an entirety by the reference character 3, the inlet valve 4 and discharge valve 5, and: the screen or straining device 6 through which the fuel passes before entering the pumping chamber 1. The membersA, B and C which preferably consist of castings, are herein illustrated as being arranged in superimposed relation, and the intermediate member B is constructed so as to form a fuel' constructed so as to serve as a removable cover or top wall for the fuel reservoir and sediment trapping chamber 7, and also as a retaining means for the screen or strainer 6 which is arranged at the upper end of the fuel reservoir 7 between the intermediate member B and top member C of the housing structure. The bottom member A serves as a housing for some or all of the parts of the diaphragm operating mechanism 3 and co-operates with the intermediate member B to support and hold the diaphragm 2 in a position where said diaphragm forms one wall of the pumping chamber 1.

Any suitable means may be used to connect or hold the housing members A, B and C in assembled relation. In the pump herein illustrated the bottom member A is adapted to be mounted on the exterior of the crank case a: of the engine to which the pump supplies fuel, and the intermediate member B is mounted on said bottom member A and clamped to same by a retaining device 8 of substantially ring shape that surrounds or embraces co-acting annular-shaped diaphragm clamping members 9 and 10 on the bottom member A and intermediate member B, respectively. The retaining ring 8 has parts 8 of any suitable shape and construction that lap over or engage the diaphragm clamping members 9 and 10 in such a way as to securely hold said members in operative relationship and cause them to tightly grip the peripheral edge portion of the diaphragm 2, but at the same time permit said clamping members to be separated easily when inspection, repair or replacement of the diaphragm becomes necessary. The removable cap or top member C is preferably provided, on its underside with a recess that receives the upper edge portion of the intermediate member B, or a gasket 11 that is used to produce a tight joint between the members B and C.

Any suitable means may be used to hold the members B and C in assembled relation. The means herein illustrated for that purpose consists of a hollow cap screw 12 that extends downwardly through a center hole in the top member C and is provided at its lower end with a threaded portion 12 that is screwed into a part of the intermediate member B, preferably, a central post 13 that projects upwardly from the bottom of the fuel reservoir and sediment trapping chamber 7 and terminates flush with the top edge of an annular portion of the intermediate member B that constitutes the side wall of the fuel reservoir and sediment trapping chamber '7. As shown in the drawing, a fuel inlet pipe 14 that leads from a source of supply of liquid fuel enters the fuel reservoir and sediment trapping chamber 7 at a point above the bottom of said chamber. The discharge valve 5 of the pump is herein illustrated as being mounted in the top member C that forms a removable cap or cover for the sediment trapping chamber 7, but this is not essential, as the discharge valve may be arranged in various other positions or in other parts of the housing structure, so long as said discharge valve is so disposed as to govern or control the escape of fuel from the pumping chamber 1 to a discharge pipe or delivery pipe 15 that leads to the apparatus which is being suppliedwith fuel by the pump.

In instances where fuel is being consumed at a more or less normal rate by the engine or other apparatus with which the pump is used, the movement of the diaphragm in one direction creates a suction in the pumping chamber 1 which causes fuel to be drawn from the fuel reservoir and sediment trapping chamber 7 upwardly past the inlet valve 4, and thence through an intake passage that leads to the pumping chamber 1, the screen 6 being so arranged that the fuel will pass through the same before reaching said inlet valve. The particular method of forming said intake passage is immaterial, and in the pump herein illustrated said intake passage is formed by a fuel duct 16 in the removable valve carrying cap 0, a fuel duct 17 in the cap screw 12 and ports or orifices 18 in said cap screw that establish communication between the fuel ducts 16 and 1'7. On the reverse stroke or movement of the diaphragm 2 fuel escapes from the pumping chamber 1 to the discharge pipe 15 by flowing upwardly through the duct 17, ports 18 and a fuel duct 19 in the cap member C that leads to the discharge valve 5.

A pump of the construction above described is inexpensive to manufacture; it is compact, and the parts of same are easy to assemble during manufacture. It has the added advantage of being of such design that the parts of same which are liable to require frequent inspection, repair or cleaning, i. e., the diaphragm, the sediment trapping chamber 'L'the screen 6 and the inlet valve are easily accessible, said inlet valve being mounted in a removable part, which, in addition to serving as a closure or top wall for the sediment trapping chamber 7, also acts as aretaining means for the screen or straining device.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. A fuel pump provided with a housing member having a pumping chamber and a fuel reservoir separated from each other by a web part of said housing member, a passage through which fuel trav from the fuel reservoir to the pumping chances-r, a diaphragm that forms one wall of said pumping chamber, said fuel reservoir being adapted to receive fuel from a source of supply, an inlet valve which controls the passage of the fuel from said fuel reservoir to said pumping chamber, and a removable cap or cover for said fuel reservoir mounted on the exterior of said housing member so as to be easily accessible, said inlet valve being mounted on said cap so as-to be removable with the same.

2. A fuel pump of the kind described in claim 1, provided with a screen or straining device for the fuel passing to the pumping chamber, arranged so that it is accessible when said valve carrying cap is removed.

a. A fuel ump of the kind described in claim 1, provided with a fuel screen or strainer that is retained in position by said removable valve carrying cap.

4. A fuel pump provided with a. housing member, a diaphragm that coacts with said housing member to form a. pumping chamber, a fuel reservoir and sediment trapping chamber formedin said housing member and arranged above said pumping chamber, said reservoir adapted to receive fuel from a source of supply, a removable cap or cover for said fuel reservoir and sediment trapping chamber, an intake valve in said cap past which fuel escapes from said reservoir when said valve is opened by the suction in the pumping chamber, and a fuel intake passage leading from said valve to said pumping chamber, a portion of said intake passage being formed in said cap.

5. A pump of the kind described in claim 4, in which said fuel intake passage also comprises a portion that extends downwardly through said reservoir and communicates with said pumping chamber.

6. A pump of the kind described in claim 4, provided with a fuel screen or straining'device arranged at *the upper end of said fuel reservoir underneath said removable cap.

'7. A pump of the kind described in claim 4, in which a portion of said fuel intake passage is formed in a part that projects upwardly from the bottom of said reservoir.

8. A diaphragm fuel pump, comprising a housing structure composed of three superimposed members, a pumping chamber and a fuel reservoir and sediment trapping chamber formed in the intermediate housing member, the top housing member constituting a removable cover for said fuel reservoir, a flexible diaphragm arranged to form one wall of said pumping chamber, an operating mechanism for said diaphragm comprising parts that are arranged inside of the bottom housing member, an intake valve for said pumping chamber mounted in the. top housing member and. adapted to be opened by the suction in the pumping chamber to permit fuel to pass from said reservoir, and a fuel passage leading from said valve to the pumping chamber.

9. A fuel pump of the kind described in claim 8, in which said bottom housing member and intermediate housing member are provided with co-acting portions that grip and hold the diaphragm of the pump.

10. A diaphragm pump, comprising a housing member provided with a recess that constitutes the pumping chamber and also provided with a fuel reservoir and sediment trapping chamber, a co-acting housing member that is adapted to house parts of the diaphragm operating mechanism of the pump, a flexible diaphragm arranged so as to form one wall of said pumping chamber, mating parts on said housing members that grip the peripheral edge of said diaphragm, an operating mechanism combined with the diaphragm, a removable cap or cover for said fuel reservoir and sediment trapping chamber, an inlet valve for the pumping chamber mounted in'said cap and adapted to be opened by the suction in the pumping chamber topermit fuel to escape from the reservoir, and a. fuel intake passageway leading from said valve to the pumping chamber and formed partly in said cap.

11. A fuel supply pump for intern'alcombustion engines and the like, provided with a housing structure composed of three members arranged in superimposed relation, the bottom member being adapted to house parts of the diaphragm operating mechanism, the intermediate member being provided with a pumping chamber and with a fuel reservoir and sediment trapping chamber, co-acting mated faces on said bottom member and intermediate member, aflexible diaphragm clamped between said mated i'aces,-an operating mechanism combined with the diaphragm, an inlet valve in the top housing member adapted to be opened by the suction produced by the movement of the diaphragm to permit iuel to escape from said reservoir, said top housing member being adapted to serve as a removable cap or cover for the fuel reservoir and sediment trapping chamber, a fuel intake passage extending from said inlet valve through said intermediate housing member for delivering fuel to the means for detachably connecting said three hous- 10 ing members together.

WILHAM 0. 0mm. 

